package com.algorithm.one2fifty;

import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

/**
 *
 * @author tuzhijin
 */
public class TwoSum_1 {

    public static void main(String[] args) {
        int[] nums = {2, 7, 11, 15};
        int target = 9;
        System.out.println(Arrays.toString(twoSum(nums, target)));
    }

    public static int[] twoSum(int[] nums, int target) {
        // 利用hash表
        Map<Integer, Integer> param = new HashMap<>(16);
        for (int i = 0; i < nums.length; i++) {
            // 目标元素减去当前元素作为判断条件
            if (param.containsKey(target - nums[i])){
                return new int[]{param.get(target-nums[i]),  i};
            }
            param.put(nums[i], i);
        }
        return new int[0];
    }
}
